Over deze norm
||Gas- en oliewinning en -productie
ISO 18871 provides methodology for measuring coalbed methane content of coal core samples obtained by coring or sidewall coring during well drilling. This standard has to be also applied to drill cuttings samples, if the equipment for the determination of the coalbed methane content according to a respective national standard is not available. The selection of the most appropriate method shall consider the purpose of the test and the possibilities of sampling. This International standard is applicable for the direct method of measuring coalbed methane content. It includes sample preparation, experimental procedures and calculation methods. Indirect methods of measuring gas content of coal (not included in this International standard) are generally based on either the gas sorption characteristics of coal under defined/specified pressure and temperature conditions. This International standard includes three types of direct measuring methods: conventional desorption (slow desorption) of core samples, fast desorption of core samples, fast desorption of cuttings or lump samples. The difference among them lies in the time allowed for gas to desorb before final crushing and in sample size and shape. This International standard is applicable for the determination of the methane content of coal during coal and coalbed methane exploration for the determination of free gas content of low rank coals is included. Procedure of free gas content determination of low rank coals need to be defined. All units used and referred to in this International standard are international standard units. Reference temperature is 0 °C (273,15 K) if not stated differently. Reference pressure is 0,1 MPa (1 bar) if not stated differently.
||Bepalingsmethode voor steenkoolgasgehalte
||Method of determining coalbed methane content